During the lifetime of a patient, it may be necessary to perform a joint replacement procedure on the patient as a result of, for example, disease or trauma. The joint replacement procedure may involve the use of a prosthesis which is implanted into one or more of the patient's bones. In the case of an ankle replacement procedure, a tibial component is implanted into the patient's tibia, and a talar component is implanted into a patient's talus. A polymer bearing insert is positioned between the tibial component and the talar component. The articular surface of the talar component bears against the articular surface of the bearing insert.